I have a 2012 FJCW (N14).

I thought I'd start with my current engine MOD list:
Boost gauge
Alta FMIC
NM Eng Hi-Flow Induction Kit
NM Eng Discharge Pipe
iPE downpipe back exhaust
DNA/BattleTuning Stage 2

I ran the above mod list on my stock tune, before I got the iPE exhaust and Battle tune, for several months with no issues. Once I got the iPE exhaust and installed it, the issues began. It took about a week for the boost to start surging/bouncing as it builds up to full boost pressure.

Imagine that when you put your foot down, beyond say 75%, for the first bit everything seems fine, then boost starts to bounce/surge as it builds up pressure, 11-12-11, 11-12-11, 12-13-12, 12-13-12, 13-14-13, etc., all the way up to full pressure. You can feel the car surging forward at each new boost peak and you can clearly hear the turbo surging/bouncing.

I took my car to the dealership because I am still under warranty. They told me with my modifications, I would need an aftermarket tune to fix the issue because my iPE exhaust provided no back pressure. I reached out to BattleTuning because I know he also has the iPE exhaust and thought his tune would, for sure, solve my boost issues. For the first few days, everything seemed ok, but then my car went right back into the surging/bouncing boost issue.

When I run the iPE exhaust in 'off' mode, I have no boost surging issues at WOT, granted the boost does not build up to 20 PSI, more like 12 PSI because 'off' mode is flow restrictive. Only in 'on' mode, fully open, do I run into the boost issue.

Yesterday, I removed the iPE exhaust, installed my stock JCW exhaust and went back to my stock tune. So far, the boost issue has been eliminated, granted its only been a day.

How could installing a downpipe back exhaust cause the boost to bounce/surge at WOT? I've modified all my turbo cars and this is a first.

I have a Evolve catted downpipe I wanted to install but I am waiting to figure out this boost issue first. I wanted to run my mods, the Evolve catted downpipe, the iPE exhaust and my Stage 3 tune. I wonder if the stock DP with the iPE is causing the issue and if I ran the Evolve DP with the iPE if there would be no issue, only one way to find out I guess (but first I want to give the stock setup another week to make sure the boost issue does not appear).

TIA

 

Compressor surge.

http://www.turbobygarrett.com/turbobygarrett/surge_line

 

To clarify the iPE exhaust is using the stock downpipe?

 

That is good info. Thanks. Now how do I stop it? Would the iPE and the Evolve fix it? Because obviously the iPE and the stock JCW DP causes the problem.

Yes, the turbo surging occurs with the stock JCW DP and iPE downpipe back exhaust.

 

You should contact Battle tuning and ask if your tune was written to run with a hi flow sports cat/decat. I would think stage 2 would automatically mean you would be. As far as I know the S and JCW downpipe are the same 400 cel with a NOx filter on top.

 

I sent him the mod list from the first post when I was talking with him about his tune and whether it would work for me, before I got the Evolve DP and after I put on the iPE exhaust. He gave me a Stage 2 map and told me that I would be able to run Stage 3 once I put the Evolve high flow catted downpipe on.

I've reached out to him and he told me it doesn't sound like it's the tune and so it must be the exhaust. I know he is the only other person I've seen running the iPE exhaust as well, granted his is the full turbo back exhaust, not just the downpipe back, so I thought getting his tune would for sure solve my issues. Maybe I need to run the stage 3 tune, Evolve DP and iPE and see what happens...

I also asked if I should be running a Stage 1 tune for the time being seeing that I am running the stock JCW DP and stock JCW exhaust. He told me that his tunes are safe to run with the JCW exhaust, so I think I can run Stage 2 with it (but I am going to reach out to him and clarify beforehand). - Update, he got back to me, "If you run the stock JCW DP, then you'll have to go back down to the Stage2 map, but if you kept the aftermarket DP and your JCW catback, it would be fine for Stage3."

 

I'm wondering if the stock cat is causing too much exhaust manifold pressure and causing your wastegate to flutter?

Definitely talk to Battle. A simple aftermarket exhaust should not cause any issues. Does the iPE tap into the ECU? Was this done correctly? Also can you monitor your EGTs? This might give you an idea of what is going on.

 

That is very low boost for a JCW less than what an S run's from the factory. Are you sure you didn't melt your cat running the stage 2 tune or its not block with oil.

You might be better off changing the downpipe for the evolve because if your cat is blocked you'll on your way to a new turbo.

 

- The Turbo surge occurred before I had the tune and continued after installing it. So it can't be the tune because it was happening on the stock tune.
- The iPE exhaust does not tap into the ECU. It does tap into the turbo vacuum line (uses this to open and close the valve). Yes, I installed it 100% correctly.
- I am picking up an obdII dongle and buying the Torque app so I should be able to monitor my EGTs soon.

BattleTuning told me I could run my current mods with my stock JCW DP and stock JCW catback safely with a Stage 2 tune and if I put the Evolve DP on and used either the stock JCW or iPE exhaust, then I could run Stage 3.

Specifically what pressure are you speaking about? On my stock tune my boost gauge reads about 14/15 PSI holding with a peak of about 18. The Stage 2 tune was giving me about 20PSI holding and peak. I have not run the Stage 3 tune because I have never installed the Evolve DP. The 12 PSI holding is because the iPE is a valvetronic exhaust and when put in 'off' (quiet) mode, the exhaust flow is restricted.

I'm not having any issues with the stock tune, stock JCW DP and stock JCW downpipe back exhaust, so I don't think my cat is blocked.

I think my next steps are to run the Stage 2 tune with the stock JCW DP and Stock JCW downpipe back exhaust and see what happens. Then run the Stage 3 tune with the Evolve catted DP and stock JCW downpipe back exhaust. Then if there are no issues, run the Stage 3 tune with the Evolve DP and iPE downpipe back exhaust; hopefully this setup will run smoothly...

 

OK sorry I thought that 12 psi was your peak boost. I don't know how the IPE exhaust works but in closed mode it sounds like it's more restrictive than stock?

If your battle tune has coded out the CEL for the downpipe(definitely should be for your stage 3) you might as well change it. You haven't mention a CEL popping up which makes hard to diagnose.

 

Yea, the 'off' mode is more restrictive than stock.

The battle tune does code out the CEL. I have never installed the Evolve high flow catted downpipe though, the issue has been with the stock JCW DP and the iPE exhaust with both stock and aftermarket tunes.

 

Let me summarize:

1.) Stock tune, stock DP, stock JCW exhaust - runs great.

2.) Stock tune, stock DP, iPE exhaust in "open" mode - runs great

3.) Stock tune, stock DP, iPE exhaust in "closed" mode - compressor surge

I can't imagine that the iPE in "closed" mode is more restrictive than the stock JCW exhaust. So if it really is a problem from the iPE exhaust and not just coincidence then I would start looking at the vacuum line that you tapped into. Not sure how the logic works regarding the vacuum opening or closing the valve but maybe when in "open" mode it creates a leak.

 

Good idea, here is my summary:

1.) Stock tune, stock DP, stock JCW exhaust, with the iPE vacuum lines connected but plugged - runs great

2.) Stock tune, stock DP, iPE exhaust in "open" mode, with the iPE vacuum lines connected - compressor surge

3.) Stock tune, stock DP, iPE exhaust in "closed" mode, with the iPE vacuum lines connected - runs fine, low boost

4.) Stage 2 tune, stock DP, stock JCW exhaust, with the iPE vacuum lines connected but plugged- ???

5.) Stage 2 tune, stock DP, iPE exhaust exhaust in "open" mode, with the iPE vacuum lines connected - compressor surge

6.) Stage 2 tune, stock DP, iPE exhaust exhaust in "closed" mode, with the iPE vacuum lines connected - runs fine, low boost

7.) Stage 3 tune, Evolve DP, stock JCW exhaust, with the iPE vacuum lines connected but plugged - ???

8.) Stage 3 tune, Evolve DP, iPE exhaust in "open" mode, with the iPE vacuum lines connected - ???

9.) Stage 3 tune, Evolve DP, iPE exhaust in "closed" mode, with the iPE vacuum lines connected - ???

 

What's limiting the boost in closed mode?

 

NAM member ra2fanatics has the same exhaust except he's also got their dp as well you could try contacting him he might have some ideas.

Is it possible to lock it in open position and disconnect the vacuum pipe and see it you can isolate the problem to a possible problem with the vacuum, vacuum is also used to move the wastegate. A catback shouldn't create any problems guys on here have done all sorts of things like straight pipe split into two tips.

 

- ra2fanatics is Battle Tuning, so I have reached out to him. You can see his replies above.

- Yes, there is 'auto', 'on' and 'off modes. If put it in 'on', it stays open.

One things to note, is that right now I am running the stock DP and stock exhaust but I did not remove the vacuum lines that I ran for the iPE. I just plugged the end that would have connected to the valve in the exhaust. So I really don't think it is the vacuum line because the car is running just fine right now.

 

There is a valve in the exhaust right before the muffler, see photo below, that the vacuum line connects. When it is closed, the flow of the exhaust is greatly reduced to reduce the noise level. This reduced flow is what causes the reduced boost pressures (at least this is my understanding and someone can correct me if I am wrong).

 

The only thing that really makes sense is that something is defective in the valve. By disconnecting and plugging the vacuum line you are eliminating this defect, and you see this because the engine performs fine.

I think that you will find your issue in the exhaust valve.

Maybe iPE will replace it. Unless someone stuck a banana in the tailpipe, a cat back system should not cause issues.

 

I am not convinced its the valve since I haven't tested the Evolve DP with the iPE yet. The valve opens and closes no problem because I can clearly hear the tone difference and how much boost is made.

If I am slow on the throttle I can build up to 20 psi without compressor surge. Its only when I quickly put the pedal to the flow that the surge occurs. (when I run the setups from post #13, numbers 2 and 5)

I agree that a catback should not cause problems, so this is very frustrating, especially since this system was so damn expensive and ra2fanatic has the full system without issues.

I just flashed Stage 2 and I am going to run around today on the stock DP and stock exhaust to test out this setup, then later tonight I will install the Evolve DP and run it with the stock exhaust and Stage 3 tune tomorrow. Then at some point next week, if there are no issues with that setup, I'll put the iPE back on, to run with the Evolve DP and Stage 3 tune, and see how it goes (I am hoping that this is the solution).

 

and blowing the welds on the intake?!

 

iPE NA got back to me today - "The surging is most likely be cause by the stock compressor recirculating valve not being able to handle the increased flow rates. It is a common problem with tuned MINIs and especially MINI's with Automatic's and or ECU tuning. I would suggest looking into replacing the recirculator valve with a higher performance unit from ALTA or Forge."

 

The ALTA or Forge DV come with different springs, my Forge unit has stiffer springs to use when boost levels increase. I believe your stock unit can't handle your increased boost.

 

I think that iPE is passing the buck. While there might be some truth in what they say regarding the diverter valve you are experiencing the surge at WOT where the diverter valve does NOT factor in.

Surge happens when boost pressure is high but air flow is low. You're trying to cram more air than the engine can take. So installing a higher flowing cat back exhaust should definitely NOT cause surge.

You need to figure out what is causing the restriction to air flow. The only thing that changed was the iPE exhaust.

I keep going back to the exhaust valve and the vacuum lines. If for whatever reason the exhaust valve is cycling (may be due to a weird vacuum signal) this could cause a restriction and the surge. Is there a way that you can manually lock the exhaust valve open without hooking up the vacuum lines and try it like that?

Regarding the lower boost pressure with the exhaust in "quiet" mode. This itself should not cause lower boost pressure (I could see it causing surge). It seems that the vacuum lines are doing something to lower the boost pressure. It would be nice to know exactly how this exhaust works.

 

the ecu controls boost via an electric solenoid supplying vacuum to the wastegate mounted on the turbo ... is it possible there is not enough vacuum available causing the wastegate to not operate properly?

 

A leaking diverter valve will cause a boost leak not a boost surge. My car is an auto with the original diverter boosting to just shy of 22psi no problem.

I know that system cost a lot of mulla and I'd be pissed too if it was causing problems.

Is there an iPE dealer nearby that can take a look and rule out the exhaust causing the problem.